Beachgoers in picturesque Wellfleet—a Massachusetts beach town nestled on Cape Cod—have been disappointed several times this month by the errant bowels of marine mammals. The beach failed multiple water sample tests, which revealed high levels of the bacteria coliform, an indicator of unsanitary conditions. The culprit, according to CapeCod.com (spotted by the killer poop-dar of an Atlas Obscura reporter), is probably seals, who apparently can’t stop pooping everywhere.

Coliform bacteria, including fecal coliform, isn't dangerous on its own, but indicates the likely presence of disease-related organisms. All area swimming beaches are tested weekly, and only Wellfleet failed this recent round of sampling. It’s the first time it’s closed in years, according to the Cape Cod Times.

While scientists can’t trace the fecal coliform back to a specific species—land mammals are just as likely to be responsible as sea mammals, since their poop can wash into the water after storms—they think that in this case, those cute seals are the poo-prit.

“We do have seaweed that floats in and out and traps seal feces so it could be a function of seaweed plus seals,” Suzanne Grout Thomas, the beach’s administrator, told CapeCod.com.

“When it came down, it was fast and furious,” she told the Cape Cod Times of the recent rains, but the description could just as easily be about the animal poop that no doubt rushed down to the water in the process.

The beach passed its third test and opened back up on Tuesday (August 30), so it's safe to go back in the water—at least for now.

[h/t Atlas Obscura]

Know of something you think we should cover? Email us at tips@mentalfloss.com.